Anterior Ligament Tear (ACL)

Anterior Cruciate Ligament (ACL) Tear

Introduction

Anterior cruciate ligament tear is a common injury for most athletes in sports such as basketball, football, soccer and more. The bone structure of the knee joint is formed by three parts: femur, tibia and patella. The knee is hinged joint joined together by the medial collateral (MCL), lateral collateral (LCL), posterior cruciate (PCL), and the anterior cruciate (ACL) ligaments. The ACL is one of the main ligaments that connect the femur and tibia. It runs in the diagonally across the middle of the knee to prevent the tibia from sliding out and in front of the femur. It also provides rotational stability.

Once the ACL is injured the other ligaments and cartilage around it are often damaged too. A partial tear is possible however rare, more common is a complete tear or close to complete.

Causes

As mentioned above, this injury is common in athletes in sports like football, basketball and soccer. ACL tears occur as a result of rapid direction changes, improper landing from jumps, and collision in the knee with other players, all of these are common occurrences in these three sports.

Symptom

There are several symptoms that can be experienced from an ACL tear. Some of them are the following:

Popping sounds during the injury

Swelling in the knee

Pain in the knee

Weakness in the knee or the feeling of it giving out

Immobility, particularly even straightening the knee is difficult

Possibly warm in the knee

Pain when activities force strain in the knee joint

Tightening feeling in the knee

Risks

There are some risks factors that lead to the possibility of a torn ACL. The following risks are discussed:

Gender

Studies have shown that females have a higher likelihood of getting a torn ACL, especially in sports compared to male athletes. It has been concluded that this is due to differences in physical structures, muscle strength, and neuromuscular control such as jumping and landing patterns. Other factors have also been considered to be responsible such as the pelvis and lower extremity alignment and loose ligaments.

Sports

Plenty of ACL injuries resulted from agility sports. Sudden movements such as pivoting, cutting, twisting, jumping or any other movement that quickly changes direction can easily result to an ACL Tear. These movements although possible anywhere is most common in sports such as basketball and football.

Contact

Plenty of ACL injuries can happen without contact. However, when something comes in contact with the knee, the risk is much higher. A collision on the knee when the knee is slightly bent or hyperextended and the foot is planted on the floor, can possibly cause an ACL injury.

Aging

Of course, the older a person is the more the ACL is rendered weak which overall increases the risk of it being torn with sudden movements, maybe even small ones. Most ACL injuries happen between ages 15 and 45 because that is when a person is prone to more activity and movement. It’s the beginning and peak of sports participation.

PREVENTION

There are ways to prevent the occurrence of an ACL tear. The following are discussed but based mainly on those with high risk factors such as athletes and women:

Warm Up

Athletes can reduce the risk of having ACL tears by warming up. It’s highly important to get blood circulating in your joints and muscles before the game. Since the best way to protect the ACL is through supporting the muscles that surround it by warming them up before putting them to work.

Stretch

Increased flexibility can help you move freely and keep the ideal form. Just as mentioned in the first step, these muscles surrounding the knee must be strengthened to properly support the body’s weight. Stretching is one of the essential ways to do that. The muscles need enough flexibility to allow the joint mobility in full range. The ligaments could easily get affected if the muscles aren’t able to function as well as they should. Include stretches for highs, calves, and hips, and particularly parts that feel tight.

Strengthening leg muscles

Strengthening leg muscles can stabilize the knee joint because it removes unnecessary strain from the knee. Especially strengthening leg muscles, will reduce the chances of an ACL tear injury. It helps stabilize the knee joint.

Plyometric Exercises

Plyometric exercises are high intensity jumping exercises. It helps strengthen the muscles to protect the knee. In doing these exercises, it’s important to know how to land. First on the balls of the feet and slowly to the heels, with knees bent and hips straight.

TREATMENT

Mild injuries are often administered with proper first-aid methods in order to decrease the pain and swelling in the knee immediately after the injury. The following are necessary steps in administering first-aid to those who have mild ACL injuries.

Rest

Of course, rest is necessary to remove any strain on the knee joint and aid in the healing process. One should be mindful to alleviate weight from the affected part. Crutches are helpful in making sure to limit using it in supporting weight.

Ice

The injured knee should be iced for every two hour intervals for a twenty minute period. This will help reduce the swelling on the injured part.

Compression

The injured knee should be wrapped in elastic bandage or compression wraps.

Elevation

One should lie down with the affected knee propped up on pillows.

If the necessary first aid doesn’t alleviate the pain nor improve the stability of the knee, then there are two types of treatment for a more severe ACL injury: Non-surgical and surgical treatment. The kind of treatment that will be conducted will depend on the severity of the injury. In order to determine the treatment necessary for a patient’s condition, a physical examination and imagery tests will be conducted. The physical test alone can be sufficient enough for the diagnosis, but in order to rule out other causes, these other tests are also made:

MRI (Magnetic Resonance Imaging) – It uses radio waves and strong magnetic fields to create images that will show the severity of an ACL tear and other signs of damage to the surrounding tissues, ligaments and tendons.

Ultrasound – It uses sound waves to create internal images. It too is used to check injuries in tissue, ligaments and tendons in the knee.

X-Ray – It is used to check for bone fractures since unlike the two previous imagery tests, the X-Ray cannot produce an image of the soft tissues, ligaments and tendons.

Other factors that will be considered for the necessary treatment includes regular activities and stability. Those with partially torn ACL often qualify for non-surgical treatments such as rehabilitation and physical therapy for at least three months. However, complete tears on the other hand will more often than not need surgical treatment. Rarely do individuals who have complete tears is free from excruciating symptoms.

Nonsurgical Treatment

Non-surgical treatments focus on recovery and rehabilitation to restore the mobility and stability of the affected knee joint. It will often employ the use of hinged knee braces. A physical therapist will be working closely with the patient to address proper biomechanics. The therapy may take a couple of days per week in order to restore the knee near its condition before the injury. The whole rehabilitation process may last for several weeks. The aim is to strengthen the muscles around and restore mobility in the knee. The therapy can be conducted at home with supervision. Crutches are also usually employed to help keep unwanted strain on the knee from the weight. Non-surgical treatments however, work best with those who are relatively inactive and are involved in activities that places less stress on the knees. It also works best with those who may suffer complete tears but suffer not instability and symptoms. Also, it includes children since their growth plates are still open. Some patients may suffer secondary injury because of repetitive instability issues in the affected knees.

Surgical Treatments

With or without surgery, patients are usually sent to physical therapy, since stiff, swollen, decreased mobility in knees during the surgery can cause significant problems in increasing mobility after surgery. Sometimes the braces may be procured to aid in the initial healing prior to the surgery.

The ACL tear is not really sown using sutures because they have proven to be unsuccessful in overtime. Hence, a complete replacement is made by using a graft composed of tendon. The ligament must be reconstructed. There are different tendons that can be used such as Patellar tendon which runs in the knee cap and the chin bone, Hamstring tendon which are at the back of the thigh, Quadriceps tendon which runs in the knee cap into the thigh, and Allograft patellar tendon. The kind that will be used will be discussed together with the orthopaedic surgeon to determine the kind that is necessary for the patient. This tendon acts like a platform for a new ligament to grown on. The regrowth process takes an ample amount of time and will require the average athlete to keep from sports for about six months and even more.

Surgical Procedure

Anethesia to be used for the surgery is selected by the patient, the surgeon and the anesthesiologist. The actual surgery begins with an examination of the affected knee while the patient is relaxed after the administration of the anesthesia. Once the physical examination suggest a torn ACL, the tendon to be used for the autograft will either be harvested or thawed and prepared according to the appropriate size. For an autograft, it is harvested while for an allograft it is thawed.

Once the graft has been prepared, an arthroscope is inserted into the joint. Small incisions are made in front of the knee in order to insert the arthroscope. The arthroscope is a thin flexible fibre optic scope fitted with a miniature camera, a light source and precision tools at the end of flexible tubes. With the use of other instruments as well, the surgeon examines the knee. The surgeon repairs or trims meniscus or cartilage injuries and the torn ligament stump is removed.

It is common for bone tunnels to be drilled into the tibia and the femur in order to position the ACL graft in the same place the torn ACL was. After that, a long needle is passed through the tunnel in the tibia going up to the femoral tunnel and then comes out in the skin of the thigh. The sutures are placed in and through the needle’s eye and then up through the tibial tunnel and to the femoral tunnel, the graft is pulled to position. It is fixated through posts, screws, spiked washers and staples, and these are not removed.

There are other ways to perform the surgery depending on the surgeon’s preference and special circumstances of the patients. The following are examples of these varations: two incision, over-the-top and double bundle.

Near the completion of the surgery, the graft is tested for tension and mobility. The surgeon performs tests such as the Lachman’s test to check for stability. Finally, the skin is closed and the necessary dressings are applied.

Autografts

Patellar tendon autograft

As mentioned above it is made up of the patellar tendon together with a bone plug from the shin and the knee cap. It is often called as the ‘gold standard’ for ACL replacements. It mostly used for those with intense athletic activities and those with jobs that don’t involve a lot of kneeling. When compared with the hamstring autograft, the rate of failure was much lower in the use of patellar tendon in terms of outcome. However, it has had increased reports on postoperative pain behind the kneecap and other problems.

Hamstring tendon autograft

It is made up of the hamstring tendon in the inner side of the knee. Sometimes, the gracilis which is in the same area is also used by some surgeons. Unlike the patellar autograft there are less complaints with regards to harvesting the graft which means less associated pain in the knee and kneecap. It only requires small incisions and has proven to result in faster recovery.

However, there has been evidenced decrease in strength in the hamstring autograft after surgery. It is believed that due to lack of fixation in the bone tunnels, because of the absence of bone plugs, it is limited in strength. In research studies, some results have shown that it is more prone to elongation which increases laxity during objective testing. Therefore, some physicians recommend the use of the patellar tendon autografts especially for those with high mobility rates in their day to day activities.

Quadriceps tendon autograft

It is made up of the middle third of the quadriceps tendon and a bone plug from the knee cap. Often a larger graft used for patients who are tall and heavy. Also, it used for patients who have failed previous ACL replacements. Unlike the hamstring graft, the incisions are more invasive, and compared to the patellar graft, it has less solidity in its fixation because only one side has a one plug. Like the patellar graft, it is also reported to yield postoperative anterior knee pain.

Allografts

It is made from cadavers and are increasing in popularity. Like the quadriceps autograft, it is also used for patients who have failed previous ACL replacements. However, they are also good for initial reconstruction. Just like the hamstring autograft, it does not incur pain in retrieving the graft from the patient and is minimally invasive since it also requires smaller incisions. Just like the patellar tendon autograft, it also has strong bone fixations. Lastly, it has decreased surgery time.

The downside of this graft is that it is often associated with infections which include viral transmissions such as HIV and Hepatitis C even with careful screening and processing. There have been reported deaths relating to infection from the allograft. However, it has led to improvements in testing and processing techniques. Just like the hamstring tendon autograft, it too has evidence in some studies where they may be prone to elongation. Some evidence also suggests that it has a high rate of failure for ACL replacement, and consisted mostly of young patients who are active and participating in high-demand sports after the surgery. It is however still unclear. There may be plenty of other reasons for this failure and will require more thorough research.